Chinese President Xi Jinping made a high-profile speech regarding Taiwan on Jan. 2 to mark the 40th anniversary of the 1979 “Message to Compatriots in Taiwan.” That 1979 speech was the Chinese government’s first policy overture to Taiwan, which replaced “liberation of Taiwan” with “peaceful unification” as the goal. Xi’s speech marking the occasion has generated heated debates about Taiwan-China relations.

Based on Taiwan’s official reactions so far, one can expect a stormy relationship between the two sides in the next couple of years — a battle that is sure to become part of the current tensions between the United States and China.

Right after World War II, the Chinese civil war resumed between Chiang Kai-shek’s nationalist forces and Mao Zedong’s communist guerrillas. Chiang was defeated and moved his Republic of China government to Taiwan, while Mao declared the founding of the People’s Republic of China on the mainland in 1949. The two sides remained bitter enemies and had no official contact during much of the Cold War. Relations gradually improved since the 1980s as Taiwan lifted martial law and the mainland started to open up.

Over the years, a distinct Taiwanese identity has grown while the Chinese identity has declined in Taiwan. Since Taiwan became a multiparty democracy, cross-strait relations have become more complicated. But when Ma Ying-jeou was in power in Taiwan from 2008 to 2016, Taiwan-China relations were stable and friendly, and cross-strait exchanges were dynamic.

That changed with the election of the Democratic Progressive Party’s Tsai Ing-wen as president of the Republic of China in 2016, and the relationship between Beijing and Taiwan has been characterized by stalemate over the past few years. From Beijing’s perspective, 2019 was a fitting time to send a new message — and a new warning — to Taiwan. A man with a sense of historical mission, Xi has been seriously eyeing Taiwan as part of his “Chinese dream” of national rejuvenation. As he stated confidently in his speech, Taiwan must and will be united with the motherland.

In his speech, Xi reiterated Beijing’s long-standing policy toward Taiwan, with “national unification” as the objective and “One Country, Two Systems” as the model. In this sense, Xi’s speech is a continuation of previous official statements, which focused on Beijing’s intent for peaceful reunification and cross-strait exchanges while reserving the right to use force, if necessary.

But Xi’s speech also contained something new. First, he introduced more flexibility to the “One Country, Two Systems” model proposed for Taiwan. That’s important, because China operates under a “One Country, Two Systems” model elsewhere, in its relationship with Hong Kong and Macao. Xi is undoubtedly aware of the grim reality in Hong Kong, where frustration is growing over how Beijing has rapidly undermined the city’s political institutions, democratic activism and media freedom.

Not wanting to replicate that situation with Taiwan, Xi is making a significant policy adjustment. In contrast to the Hong Kong case, where the “One Country, Two Systems” model was imposed in 1997 without input from the Hong Kong people, what Xi is suggesting is involving the Taiwanese in developing a new model for Taiwan. The move injects a level of self-determination for Taiwan into the unification model.

Xi also proposed that representatives from different parties and walks of life in Taiwan should join Beijing in political consultations to discuss cross-strait relations and make political arrangements for Taiwan’s future. This might be the most intriguing and innovative part of his speech since it essentially kicks off the unification process by sidestepping the unpopular governing party. He did not set a timetable for unification, but this proposal, if implemented, would represent a giant stride toward Beijing’s goal of unification with specific steps being taken to prepare for the future.

It is unfortunate that the Tsai administration immediately and categorically rejected Xi’s proposal without much deliberation. Were the Tsai administration open to discussions, or willing to offer a plan to improve cross-strait relations, Taiwan could use its vibrant democracy as a tool to shape the future of the Chinese mainland. Beijing says anything can be discussed under “one China”; Taiwan certainly can and should raise its preconditions for unification. That would put tremendous pressure on the mainland to move toward democratization.

Tsai’s position toward the mainland hardened last year. Now she only uses “China” to refer to the mainland instead of the more conciliatory “Chinese mainland” that she used during her first year in office. In Taiwan, when politicians refer to the mainland as “China”, it’s a clear indication of their anti-China and pro-independence position.

Tsai’s shift toward a more hard-line approach has many possible causes: loss of five diplomatic allies of the ROC during her term so far; perceived “bullying” by Beijing in international arenas; her strategy to play the China card to deflect internal discontent toward her lackluster performance; and her party’s loss in local elections last year.

Though Xi has offered more flexibility in the unification process, it is clear that Beijing’s “wait and see” attitude toward Tsai is over. China’s Taiwan Affairs Office has for the first time publicly lashed out at Tsai as a “separatist.” It’s almost certain that Tsai will become more hard-line before the 2020 Taiwan elections as she struggles to be reelected. Her leadership has been disappointing to most Taiwanese, including her supporters. To be tough on China and brand herself as a leader to defend Taiwan’s sovereignty may help her win back some votes.

Xi’s firm determination and Tsai’s strong resistance suggest that the Taiwan Strait will not be calm in the next couple of years. That has real implications for the United States. Tsai will strive to strengthen relations with the United States while maintaining an anti-China stance. And there is reason to believe Washington will be amenable to her overtures. President Trump signed several pro-Taiwan bills into law in 2018, including the Taiwan Travel Act and the Asia Reassurance Initiative Act, moves that Beijing resents.

The U.S. government will likely continue to play the Taiwan card when dealing with China, but Taiwan’s people must be cautious and sober. It is not inconceivable that someday Trump may decide to sell out Taiwan in order to strike a deal with China. Taiwan’s future is inextricably linked to China’s. Instead of turning away from China, Taiwan may wish to work with Beijing and seek a mutually acceptable outcome for the island democracy.

This post has been updated.